198 WOOD NOTES WILD. 
Rourrep Grouss. — Contin. 
this rapid vibration causing the rolling noise with which the sound termi- 
nates. The movements of the wings, and the rumbling thereby produced, 
are entirely analogous to those produced by the humming-bird, when 
hovering over a flower. This I believe to be the true description of the 
manner of drumming, and I am happy to add that my father, who has 
often crawled up to within twenty feet of the bird at such times, corrobo- 
rates it in every particular. There are, doubtless, among those who read 
the ‘Sportsman,’ many who have had opportunities to watch the operations 
of the ruffed grouse when engaged in drumming, and the experience of 
each one would be a very acceptable contribution to our knowledge of the 
habits of this very interesting species. 
“©The fact that the drumming of the ruffed grouse is heard as often in 
autumn as in spring has raised the question of why this sound is produced. 
In regard to this, Nuttall is probably correct in saying that it is often ‘an 
instinctive expression of hilarity and vigor,’ as well as the call-note of the 
male during the breeding season.’ 
“ To this article Mr. J. H. Batty replies in the following terms : — 
“Tn No. 21 of the ‘Sportsman’ I find an article of my friend, Mr. Ridg- 
way, ‘Why and how does the ruffed grouse drum?’ I solved the 
mystery, to my own satisfaction, some five years ago, when living at 
Springfield, Mass. The peculiar noise made by the ruffed grouse is 
caused by the backs or exterior sides of the wings striking each other as 
they are forcibly raised over the back of the bird. Ihave seen the grouse 
drum, within a few yards of me, a number of times. On one occasion I 
was sitting on a log in the woods, by a stone wall, eating my lunch. 
While thus engaged, a ruffed grouse mounted the wall, about fifty yards 
from my position, and commenced walking on it directly toward me. I 
immediately lay down behind the log on which I had been sitting, and 
awaited the approach of the bird. When it had reached a point opposite 
me it mounted a large elevated stone on the’ top of the wall and com- 
menced drumming, after a series of struttings backward and forward on 
the wall, as described by Audubon, Wilson, and others. When the bird 
was drumming, its back was toward me, and I had an unobstructed view 
of it against the sky. The grouse first struck its wings together slowly: 
and strongly, then gradually increased these strokes until the single strokes 
could not be detected. During the more rapid beating of the wings the 
‘semi-circular haze’ caused by the wings was observable, as stated by Mr. 
Henshaw. The wings of the grouse were stiffened, and the strokes given 
from the shoulder (if I may so speak); and the wings did not appear to 
touch the bird’s sides. , 
